The present invention relates to clamping bands for cable bundles and more particularly to a clamp for electrically and mechanically securing a tubular shielding sleeve of the cable to the body of a connector for the cable.
A clamping band for electromagnetic shielding is described in my prior U.S. Pat. No. 4,646,393, which is incorporated herein by reference. This prior band clamp, shown as 10 in FIG. 1, has a single strip of metal forming a strap 12 with an integral buckle 14 at one end, the opposite end of the strap 12 being passed through the buckle for forming a loop that is tightened around a cable sleeve 16 when tension is applied to an extending portion 18 of the strap 12, the strap being doubled over the buckel to secure the clamp 10. A conventional pulling tool such as described in the prior patent can be used for applying the tension, bending, and trimming the strap 12.
As also set out in the prior patent, it is highly desirable that a single configuration of this type of clamp be usuable over a wide range of cable diameters. This is important for reducing fabrication and stocking costs, and for avoiding the selection of an improper band from a set of differing sized bands. Cables that are typically encountered range in diameter from about two inches down to less than 0.250 inch, even as small as 0.156 inch. In the prior patent, clamping down to the smaller sizes is facilitated by providing a transverse slot 20 in the inside of the buckle 14, forming adjacent loops 22 and 24 that move together as the strap 12 is tightened, allowing the loops 22 and 24 to bend in an arcuate manner for closely conforming to small sleeve diameters.
As shown in FIG. 1, a disadvantage exhibited by the clamp bands of the prior patent is that while they are capable of clamping down to the 0.156 inch diameter, the sleeve 16 is subject to damage by being pinched at 26 between the loops 22 and 24 of the buckle 14 as they move together.
Thus there is a need for an improved band clamp that is better able to conform to a small diameter cable without damage to a sleeve of the cable, that is easy to install and use, and is inexpensive to produce.